Hydrocarbon oil conversion



Aug; 18,1936. J. G. ALTHER HYDROGARBON OIL CONVERSION Original Filed Nov. 4, 1929 Reissued Aug. 18, 1936 UNITED STATES PATENT OFFICE Original No. 1,991,440, dated February 19, 1935,

Serial No. 404,629, November 4, 1929.

Application for reissue April 11, 1935, Serial No.

12 Claims.

This invention relates to the art of treating hydrocarbon oils and is particularly directed to the conversion of relatively high boiling oils into low boiling products of a more valuable nature.

When heavy oils which contain or produce upon substantial conversion a product containing objectionable quantities of pitchy or finely divided carbonaceous material are cracked by ordinary means, maximum conversion is restricted and consequently the production of light products such as those suitable for motor fuel is penalized if the resulting residual oil is to be of such nature that it will meet specifications for a good quality commercial fuel.

complished simultaneously, each augmenting and assisting the other.

In the drawing forming a part hereof there is shown in side elevation an apparatus partially in cross section wherein the process of my invention may be practiced.

Oil is fed from supply tank I, through valve 2, pump 3, line 4, valve 5, preheating coil 6, valve 'I and line S, into dephlegmator 20. A portion or all of this charging stock may pass through valve 9 and line I directly into fractionating tower 23. That portion of the preheated charging stock not vaporized in dephlegmator may pass together with the reflux from the bottom of de- 15 The present invention provides for a substantial production of the more valuable light products and at the same time permits the production of marketable fuel as a residual product. The purgp pose of the invention is two-fold-rst to obtain the maximum desirable conversion of the oil undergoing treatment thereby obtaining a high yield of the most valuable products from the cracking reaction, and second, to retard and minimize the formation of those components in the residual oil which are detrimental to its use as a fuel or for reconversion and to remove or change the character of such components which may be formed. Both objects in part may be accomplished by the reconversion of various intermediate products from the first cracking reaction under conditions more suitable than .those maintained in the first cracking zone. The second object may be further fulfilled by blending with the residual products some of the more refractory intermediate or final products either from the first or the second cracking reactions and to cool, if necessary, and filter the resulting blended residual material and finally'to again blend the filtered residual product with an intermediate product from within the system. In this Way a residual product Vmay be obtained which may be marketable as a fuel or may be suitable for reconversion in the same or another process. This blending may be done either in the reaction chamber or in the flashfchamber and the blending material may be either relatively hot or cold, may be in a vaporized or a liquid state or partially in either state and may be a final or intermediate product ofthe process.

In the process which constitutes my invention both of the above mentioned purposes may be :ac-

phlegniator 2li, through line I I and pump I2 into the heating element I3. Heating element I3 is located in any suitable furnace I4 and the oil passing therefrom having been heated to the desired outlet temperature may pass into reaction chamber I'I, through valve I5 and line I 6. Vapors from 20 reaction chamber il may pass through valve I 3 and line I9 into the bottom of dephlegmato'r 20 Where, after being cooled and fractionated, the portion thereof still uncondensed at the top of the dephlegmator may pass through line 2l and valve 22 into the fractionating tower 23. In this secondary fractionating tower the vapors are further fractionated and cooled and the final light products from the system emerge as vapor 30 through line 25 and valve 24, pass through condenser 26 where they are condensed and cooled. thence through line 21 and valve 2S into receiver 29. From receiver 29, the uncondensed gases may be drawn off through valve 3D, in line 3 I and the 35 pressure on the receiver controlled thereby. Liquid may be withdrawn from the receiver to storage or elsewhere through line 33 controlled by valve 32. Required connections for feeding back this final liquid product to the top of fractionating tower 23 or dephlegmator 20 are well known to the art and are` not shown in the drawing. This may be done, however, to assist cooling and fractionation in either tower. Liquid from the bottom of reaction chamber I1 may be withdrawn through valve 34 and line 35 into a vaporizing Zone or ash chamber 36. Pressure may be reduced through Valve 34 so that flash chamber 3S may be maintained at a substantially lower 50 pressure than that in reaction chamber I1, and the latent heat from the oil which passes into the flash chamber 36 may thus be utilized for its vapor-ization. Vapors from the flash chamber 55 emerge through valve 3l and pass through line 38 into the bottom of the fractionating tower 23. Liquid which collects in the bottom of fractionating tower 23 is drawn olf through line 39 and may be pumped wholly, or in part, by means of pump 4I through valve 453, valve 42 in line 43 and into line B from which it may pass into dephlegmator 26.

A portion of the vapors from the top of dephlegmator may be drawn from line 2l through line 44 and valve G5 into the header 45. In the saine manner a portion of the vapors from the top of fractionating tower 23 may be Withdrawn from line 25 through line 52 and valve 53 into the header 46. A side stream from the fractionating tower 23 may pass through line 59 and valve 5i into the header 46. A portion or all of the liquid from the bottom of fractionating tower 23 may be diverted from line 39 through line il?, valve 48 and line 49, into the header 46. A portion of the liquid product from receiver 29 may be Withdrawn through line 54 and valve 55 and passed into the header 45. Any or all combinations of these products entering the header 46 may be picked up by pump 5'! Yand passed through line 56, valves 63 and 65, into reaction chamber IT, or by partially or totally closing valve 56 and partially or totally opening valve 65', a portion or all of these products may pass through line 56', through line 35 and into the ash chamber 3B. Similarly valve 64 may be partially or totally opened and valves ES and 6E partially or totally closed so that all or any portion of the I material fro-m line 56 may pass through valve 64 and line 65 directly into flash chamber 35. It may be desired to further convert certain of the products or certain combinations of the products which may enter the header 46. In this case Valve 58 is opened, valve 63 is closed and the desired products pass through the heating element 59 which is located in a suitable furnace 60. The heated or unreconverted products, as products from header l5 may be controlled by the conditions maintained Within the heating element 59 and the temperature in furnace 66. When it is desired to simply add heat to the products from header 46, this may be accomplished by maintaining a lower temperature in furnace 60. The heated or reconverted products, as the case may be, emerge from the heating element 59 and may pass through line 6I and valve 62, back into line Eli-from line 56 the heated or reconverted products may p-ass into reaction chamber I1 or into ash chamber 36 or both in any or all of the manners previously described.

Liquid from the bottom of liash chamber 36 Which may have been previously blended with any of the products above mentioned either in reac tion chamber I'l or in the line 35 between reaction chamber I1 and flash chamber 36, directly in flash chamber 36 or in all or any combination of these, may be withdrawn through line 5l, valve 68, pump 69, valves 16 and 16, through filter il, line 13 and Valve 19, to storage or elsewhere. In case sufficient pressure is maintained on/the flash chamber 36, pump 69 may be unnecessary and if so, may be bypassed by opening valve l2 in line 61 and closing valves .68 and 70. It is often desired to partially cool certain typesI of residual oils before they are filtered as partial cooling may render the carbon, pitchy and asphaltic materials in the residual oil less soluble and filtration may thereby be facilitated. When cooling is desired it may be done to any desired degree by closing the valve 16, opening valve 13, and passing the residual oil through cooler 14 and Valve l5 back into line 61. Filter 'il may be of any suitable type such as will retain the carbon, pitchy and asphaltic material suspended in the blended material and permit the passage of the relatively clean residual liquid. The filter 'I I, for example, may contain a bed of absorbent material such as fullers earth, bone black or the like, or may employ a filtering medium such as cotton duck, Monel metal cloth, or others. Several filters may be used ultimately if necessary to permit uninterrupted operation.

The diluted and ltered residual oil may, if desired, be further diluted by liquid from the bottom of fracticnating tower 23, any portion of Which may pass from line il through valve lil into line l. By the judicial use of the blending materials before filtering and this diluent after filtering a relatively clean residual product may be'produced having a viscosity which may be regulated over a wide range. When it is desired to produce an oil of relatively low viscosity this method permits ltering before thedegree of dilution is such as to render the carbon, pitchy or asphaltic materials dieult to filter out and provides for final blendingl to the desired viscosity after filtration.

The residual product from the process may, if desired, be re-processed inthe same apparatus and to do this, all or a portion of the residual product may pass frornline 13, through valve 80, pump 8l, line 'Il and valve 18"'in line 19 into tank I where it may mix with the charging stock or it may pass in whole or in part through line 'I1 and valve 'I8' directly into line 4 where it may also mix with the charging stock.

The following is given as an example of the operation of my process.V

Operating on a charging stock of 26 A. P. I.

mixed base topped crude oil the combined feedy from the bottom of dephlegmator 2D was fed to the heating element 3 under a pressure of approximately 350 poundsper square inch and the outlet temperature of heating element I3 was maintained at approximately 910 F. Reaction chamber I was held at a pressure of approximately 225 pounds per square inch and at a temperature of approximately 865 F. Dephlegmator 2B was also maintained at a pressure of about 225 pounds per square inch and a top tempera ture of about 575 F. Vapors entering the secondary fractionating tower 23 were reduced through Valve 22 to approximately 50 pounds per square inch and the outlet temperature at the top of this tower was about 400 F; All of the bottoms from the secondary fractonating'tower 23 were re-processed through heating element 59 under a pressure of approximately 500 pounds per square inch and an outlet temperature `of approximately 980 F. The reconverted bottoms from the secondary fractionating tower 23 were introduced into the residual oil in the bottom of reaction chamber Il through line 56. Residual oil from reaction chamber I1 entered theflash chamber 36 through line 35, the pressure'being reduced through valve 34. The flash chamber was maintained at a pressure of approximately 60 pounds per square inch. k The distil1ate'w`ith drawn from receiver 29 represented 65%- of the charging stock. This product fell Within the boiling range of finished motorfuel having an initial boiling point of k102" F., an end point of 437 F., and a lgravity of 56 A. P. I. After chemical treatment this product showed an anti-knock value equal to a benzol equivalent of 40. Residuum Withdrawn from flash chamber 36 after filtering and blending had a gravity of 11 A. P. I., a. viscosity of 84 seconds at 122 F., Saybolt furol and showed a B. S. content (material insoluble in benzol) of approximately 0.8%, Before filtering this residuum contained about 2.5% B. S.

From the foregoing it will be seen that under certain conditions I have been able to produce by my process a high yield of the more valuable products suitable for motor fuel having a high antiknock rating and at the same time have held the residual product to specifications which render it suitable for sale or use as a premium fuel oil.

Having thus described my invention, what I claim is:

, 1. In processes for cracking oil in which the oil is subjected to pressure distillation in a pressure distillation zone, the vapors and unvaporized residue separately removed from the pressure distillation zone, the vapors subjected to fractionation and the unvaporized oil to further distillation by its contained heat in a zone of lower pressure than the pressure prevailing in the pressure distillation zone, the improvement which comprises subjecting reflux condensate formed in the fractionation to drastic cracking temperature and pressure conditions and then introducing portions of said reflux condensate to said pressure distillation zone and said zone of lower pressure, and uniting and subjecting to common condensation vapors released from said zone of lower pressure and vapors taken oil from the zone of pressure distillation.

2. A hydrocarbon oil cracking process which comprises passing the oil through a heating zone and heating the same therein to cracking temperature under pressure, discharging the heated oil into a vapor separating zone and separating the same therein under pressure into vapors and unvaporized oil, removing the vapors for dephlegmation and condensation, separately removing the unvaporized oil and passing the same to a flashing zone maintained under lower pressure than said separating zone, partially distilling the unvaporized oil under the lower pressure in said flashing zone thereby forming additional vapors and residual oil, dephlegmating said additional i vapors to condense heavier fractions thereof,

heating the condensed lheavier fractions to cracking temperature in an independent heating zone, and introducing separate portions of the thus heated fractions directly into said separating zone and to said flashing zone.

3. A hydrocarbon oil cracking process which comprises passing the oil through a heating zone and heating the same therein to cracking temperature under pressure, discharging the heated oil into a vapo-r separating zone and separating the same therein under pressure into vapors and unvaporized oil, removing the vapors, separately removing the unvaporized oil and passing the same to a flashing zone maintained under lower pressure than said separating zone, partially distilling the unvaporized oil under the lower pressure in` said flashing zone thereby forming additional vapors and residual oil, fractionating the vapors removed from the separating zone and said additional vapors to condense a portion thereof, heating resultant reflux condensate to cracking temperature in a second heating zone and then introducing portions thereof into said separating zone and to said flashing zone.

4. A hydrocarbon oil cracking process which comprises heating the charging oil to cracking temperature under pressure while flowing in a restricted stream through a heating zone, discharging the heated oil into an enlarged reaction zone maintained under cracking conditions of temperature and pressure, separately removing vapors and unvaporized oil from the reaction zone, subjecting the vapors to primary dephlegmation and returning resultant reflux condena sate to the heating zone, flash distilling the unvaporized oil in a flashing zone maintained under lower pressure than the reaction zone, combining the flashed vapors with the vapors uncondensed by the primary dephlegmation and dephlegmating the resultant mixture thereby forming additional ing vapors and unvaporized oil from the reaction "i zone, subjecting the vapors to primary dephlegmation and returning resultant reflux condensate to the heating zone, flash distilling the unvaporized oil in a flashing zone maintained under lower pressure than the reaction zone, combining the flashed vapors with the vapors uncondensed by the primary deplegmation and ldephlegmating the resultant mixture thereby forming additional reflux condensate, heating the latter to higher cracking temperature than the charging oil in a second heating zone and then introducing at least a portion thereof to the flashing zone, and finally condensing the vapors uncondensed by the last-mentioned dephlegmating step.

6. In a hydrocarbon oil cracking process, the steps which comprise heating the oil to cracking temperature in a heating zone and separating the same into vapors and unvaporized oil, subjecting the vapors to dephlegmation in a dephlegmating zone and thence to fractionation in a t fractionating zone, flash distilling the unvaporized oil by pressure reduction in a flashing zone, introducing the flashed vapors to said fractionating zone to commingle with the cracked vapors being fractionated therein, removing reflux condensate from the fractionating zone and heating the same in a second heating zone to higher cracking temperature than is maintained on the first-mentioned heating zone, introducing resultant cracked products from said second heating zone into the flashing zone and returning reflux condensate from said dephlegmating zone to the first-mentioned heating zone.

7. A cracking process which comprises subjecting hydrocarbon oil to cracking conditions of temperature and pressure and separating the same into vapors and unvaporized oil, dephlegmating the vapors and returning resultant reflux v to the cracking step, flash distilling the unvapo-rl ized oil by pressure reduction and fractionating resultant flashed vapors in admixture with the vapors uncondensed by said dephlegmation, cracking reflux condensate formed in this fractionating step at higher temperature than the firstA mentioned oil and contacting resultant vapors with the unvaporized oil undergoing flash distillation to assist the distillation thereof, and finally condensing the fractionated vapors.

8. In a hydrocarbon oil cracking process, the steps which comprisey heating the oil to cracking temperature in a heating Zone and separating the same into vapors and unvaporized oil, subjecting the vapors to dephlegmation in a dephlegmating zone and thence to fractionation in a fractionating Zone, flash distilling the unvaporized oil by pressure reductio-n in a flashing zone, introducing the flashed vapors to said fractionating zone to commingle with the cracked vapors being fractionated' therein, removing' reflux condensate from the fractionating zone and heating the same in a secon-d heating zone to higher cracking temperature than is maintained on the firstnl'entioned heating zone, and introducing resultant cracked products from said second heating zone into the flashing zone.

9. The method of converting higher boiling oils into lower boiling oils which comprises heating a confined flowing stream of hydrocarbon oil to cracking temperature under superatmospheric pressure, passing the stream of highly heated oil intoan enlarged zone wherein a cracking temperature is maintained and vapors separate from liquids, passing separate-d liquids from said reaction zcne into a separate enlarged zone, maintained under lower pressure than the first-named zone, and flash distilling the same therein by pressure reduction, subjecting resulting flashed vapors to fractional condensation to separate vapors of desired boiling range from heavier fractions as condensate, passing condensate so formed through a separate heating Zone wherein it is raised to a cracking temperature, introducing resulting highly heated condensate into the first-named enlarged zone and into said enlarged vzone second mentioned, and condensing the fractionated vapors to form a desired distillate.

10. A cracking process which comprises heating hydrocarbon oil to cracking temperature under pressure while flowing in a restricted stream through a heating Zone, introducing the heated oil to a reaction Zone maintained under cracking conditions of temperature and pressure and effecting further conversion therein, removing liquid reaction products from the reaction zone and flash distilling the sam-e in a flashing Zone by pressure reduction, fractionating the flashed' vapors andv subjecting resultant -reflux condensate to cracking conditions of tempera-- ing conditions of temperature and pressure and" effecting further conversion therein,` removing liquid reaction products from the reaction zo'n and flash distilling thesame in a flashing zone by pressure reduction, fractionating the flashed vapors and subjecting resultant reflux condensate to independently controlled cracking conditions of temperature and pressure while flowing in aV restricted stream through a second heating zone, discharging heated products from the second heating zone into'the reaction zone and into the flashing zone, and finally condensing the fractionated vapors.

12.A cracking process which comprises heating hydrocarbon oil to cracking temperature under pressure while flowing in a restricted stream through a heating zone, introducing the heated oil to a reaction zone maintained under cracking conditions of temperature and pressure and separating vapors from unvaporized oil therein, removing unvaporized oil from the reaction zone and flash distilling the same in a flashing zone by pressure reduction, separately removing vapors from the reaction zone and dephlegmating the same to condense fractions thereof heavier than gasoline, returning resultant reflux condensat-e to the heating zone, further fractionating the dephlegmated vapors and subjecting lighter reflux condensate thus formed to independently controlled cracking conditions of temperature and pressure while flowing in a restricted stream through a second heating zone, introducing heated products formed in the second heating zone into the reaction zone and the flashing' Zone, and finally condensing the fractionated vapors. Y Y

JOSEPH G. ALTHER. 

